Just to finish the story (in case borisb is looking), my problem was caused because an update.zip file that was left on my SD card so that I could fix Minesweeper was interfering with the next (auto-downloaded) update of the system software. It then got stuck in a loop somehow and later would not respond at all (black screen). I sent the eDGe in and the Entourage folks fixed it right up for me. I had incorrectly thought that it didn't matter if the zip file remained on the card because I was instructed to hold down a sequence of buttons to get the eDGe to "see" that update and run it. Looks like not the case if an auto-update is triggered, so if ever anyone does a manual reinstallation using the method I used, be sure to delete or move that zip file before the next update comes along!